Here's some scripture you can show your friend to strengthen him:
"Blessed [are] they which are persecuted for righteousness' sake: for theirs is the kingdom of heaven. Blessed are ye, when [men] shall revile you, and persecute [you], and shall say all manner of evil against you falsely, for my sake. Rejoice, and be exceeding glad: for great [is] your reward in heaven: for so persecuted they the prophets which were before you (Matthew 5:10-12).
"And the brother shall deliver up the brother to death, and the father the child: and the children shall rise up against [their] parents, and cause them to be put to death. And ye shall be hated of all [men] for my name's sake: but he that endureth to the end shall be saved" (Matthew 10:21-22).
"Whosoever therefore shall confess me before men, him will I confess also before my Father which is in heaven. But whosoever shall deny me before men, him will I also deny before my Father which is in heaven. Think not that I am come to send peace on earth: I came not to send peace, but a sword. For I am come to set a man at variance against his father, and the daughter against her mother, and the daughter in law against her mother in law. And a man's foes [shall be] they of his own household. He that loveth father or mother more than me is not worthy of me: and he that loveth son or daughter more than me is not worthy of me. And he that taketh not his cross, and followeth after me, is not worthy of me" (Matthew 10:32-38).
"But he that received the seed into stony places, the same is he that heareth the word, and anon with joy receiveth it; Yet hath he not root in himself, but dureth for a while: for when tribulation or persecution ariseth because of the word, by and by he is offended" (Matthew 13:20-21)
"These things I have spoken unto you, that in me ye might have peace. In the world ye shall have tribulation: but be of good cheer; I have overcome the world" (John 16:33).